1. Technical Field
The present invention relates to a liquid ejecting apparatus such as an ink jet printer and a method of controlling the liquid ejecting apparatus, and in particular, to a liquid ejecting apparatus including a liquid ejecting head capable of ejecting a liquid in pressure generating chambers from nozzle openings by varying pressure in the pressure generating chambers communicating with the nozzle openings and a method of controlling the liquid ejecting apparatus.
2. Related Art
A liquid ejecting apparatus is an apparatus which includes a liquid ejecting head capable of ejecting a liquid and ejects a variety of liquids from the liquid ejecting head. The representative example of the liquid ejecting apparatus is an image forming apparatus, such as an ink jet printer (hereinafter, simply referred to as a printer) which includes an ink jet printing head (hereinafter, simply referred to as a printing head) serving as a liquid ejecting head and prints an image or the like by ejecting and landing liquid-like ink onto a print medium (landing target) such as a print sheet from nozzles of the printing head. In recent years, the liquid ejecting apparatus has been applied to a variety of manufacturing apparatuses such as an apparatus manufacturing a color filter such as a liquid crystal display, as well as the image printing apparatus.
A liquid ejecting apparatus is configured so as to eject a liquid from nozzles communicating with pressure generating chambers by applying an ejection driving pulse to pressure generating elements (for example, piezoelectric vibrators or heating elements), driving the pressure generating elements, varying the pressure of the liquid in the pressure generating chambers, and using this variation in the pressure. In the liquid ejecting apparatus, the amount of liquid ejected can be increased by enlarging the amplitude of pressure vibration to be applied to the liquid in the pressure generating chambers. In other words, the amount of liquid ejected can be increased by enlarging the driving voltage of the ejection driving pulse (for example, see JP-A-2003-94656).
In recent years, the liquid ejecting apparatus has tried to eject a liquid (hereinafter, also referred to as a high-viscosity liquid) having a viscosity higher than that of a known liquid such as UV ink (ultraviolet curing ink). That is, in the past, a liquid, such as water, having a low viscosity was mainly used. In recent years, however, a high-viscosity liquid with 6 mPa·s or more has been tried to be ejected. In order to eject a sufficient amount of high-viscosity liquid, it is necessary to vary the magnitude of pressure so as to correspond to the amount of high-viscosity ejected and apply the pressure to the pressure generating chambers. However, when the variation in the pressure is increased, a flying speed of the liquid becomes larger. Therefore, the rear portion of the liquid may easily grow to become a tail-like shape. Moreover, a problem may arise in that the tail-like portion separated and flying from the main portion of a liquid droplet is not landed on the regular location (desired location) of a landing target. In the ink jet printer, for example, the tail-like portion may become mist and be landed out of the regular location, so that a dot is separated. Therefore, a problem may arise in that an image quality deteriorates. In particular, in the high-viscosity liquid, since the tail-like portion is separated into several pieces, the several separated pieces (satellite ink droplets or mist) may result in deteriorating the image quality to a great extent.